title: Multi-Institutional Sharing of Electronic Health Record Data to Assess Childhood Obesity.
abstract: To evaluate the validity of multi-institutional electronic health record (EHR) data sharing for surveillance and study of childhood obesity.
  
  
  
  We conducted a non-concurrent cohort study of 528,340 children with outpatient visits to six pediatric academic medical centers during 2007-08, with sufficient data in the EHR for body mass index (BMI) assessment. EHR data were compared with data from the 2007-08 National Health and Nutrition Examination Survey (NHANES).
  
  
  
  Among children 2-17 years, BMI was evaluable for 1,398,655 visits (56%). The EHR dataset contained over 6,000 BMI measurements per month of age up to 16 years, yielding precise estimates of BMI. In the EHR dataset, 18% of children were obese versus 18% in NHANES, while 35% were obese or overweight versus 34% in NHANES. BMI for an individual was highly reliable over time (intraclass correlation coefficient 0.90 for obese children and 0.97 for all children). Only 14% of visits with measured obesity (BMI ≥95%) had a diagnosis of obesity recorded, and only 20% of children with measured obesity had the diagnosis documented during the study period. Obese children had higher primary care (4.8 versus 4.0 visits, p<0.001) and specialty care (3.7 versus 2.7 visits, p<0.001) utilization than non-obese counterparts, and higher prevalence of diverse co-morbidities. The cohort size in the EHR dataset permitted detection of associations with rare diagnoses. Data sharing did not require investment of extensive institutional resources, yet yielded high data quality.
  
  
  
  Multi-institutional EHR data sharing is a promising, feasible, and valid approach for population health surveillance. It provides a valuable complement to more resource-intensive national surveys, particularly for iterative surveillance and quality improvement. Low rates of obesity diagnosis present a significant obstacle to surveillance and quality improvement for care of children with obesity.
authors.affiliation: Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America ; Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America.
authors.forename: L Charles
authors.initials: LC
authors.lastname: Bailey
authors.forename: David E
authors.initials: DE
authors.lastname: Milov
authors.forename: Kelly
authors.initials: K
authors.lastname: Kelleher
authors.forename: Michael G
authors.initials: MG
authors.lastname: Kahn
authors.forename: Mark
authors.initials: M
authors.lastname: Del Beccaro
authors.forename: Feliciano
authors.initials: F
authors.lastname: Yu
authors.forename: Thomas
authors.initials: T
authors.lastname: Richards
authors.forename: Christopher B
authors.initials: CB
authors.lastname: Forrest
mesh_terms: D000293:Adolescent; D015992:Body Mass Index; D002648:Child; D002675:Child, Preschool; D057286:Electronic Health Records; D006801:Humans; D007373:Interinstitutional Relations; D050177:Overweight / Q000150:complications / Q000453:epidemiology*; D063766:Pediatric Obesity / Q000150:complications / Q000453:epidemiology*; D014481:United States / Q000453:epidemiology